Computertomographic characteristics of primary brain tumors in dogs and cats

Since computed tomography (CT) was introduced to veterinary medicine in the beginnings of the 80s, the CT of the skull has mainly been used for the diagnosis of brain tumors. The present study includes 18 dogs and five cats, all patients of the Clinic of Small Animals of the School of Veterinary Medicine Hannover. After a CT of their skull was made, a primary intracranial neoplasm was confirmed by a pathomorphological and -histogical examination post mortem. Four of the five cats had a meningioma, one cat an astrocytoma. With five cases the meningioma also predominated in the dogs, followed by primary lymphoma with four cases. An astrocytoma, an oligodendroglioma and a choroid plexus papilloma were diagnosed respectively in two dogs. A pituitary gland tumor, a germ cell tumor and a medulloblastoma represented individual cases. Based on the pathomorphologically and -histologically confirmed diagnosis, characteristics of these primary brain neoplasms can be found in their CT image. However, changes are not pathognomonic for a certain type of tumor; a definitive diagnosis cannot be made from the CT image.     

犬睾丸精原细胞癌一例的诊疗

介绍了1例老龄犬睾丸精原细胞癌的诊断和手术治疗.通过临床症状检查、B超检查、电解质检测、血常规检查、生化检查和肿瘤组织病理检查,确诊为睾丸精原细胞癌,运用手术方法摘除瘤体后,3个月后回访该犬正常生存,饮食正常,体重增加.     

Neoplastic pleocytosis in a dog with metastatic mammary carcinoma and meningeal carcinomatosis

Abstract: A 12‐year‐old female spayed Labrador Retriever was presented with a history of seizures and abnormal vocalization. Approximately 1 year before presentation, multiple mammary cysts had been surgically excised. A mammary mass was noted on physical examination, and 2 separate parenchymal brain lesions were found on imaging studies. Cerebrospinal fluid (CSF) collected from the cisterna magna was analyzed, and abnormalities included moderate pleocytosis with atypical discrete round cells that occasionally formed loose clusters. The dog was euthanized, and on necropsy a primary solid mammary carcinoma was identified as well as multiple metastatic foci in the brain with diffuse meningeal involvement. The cells in the CSF had a morphologic appearance similar to the cells in the primary mammary tumor and in the metastatic tumors in the brain. On immunostaining, cells from the primary mammary tumor, the brain tumors, and the CSF expressed cytokeratin. The CSF cells did not express CD18, CD3, or CD79a. A final diagnosis of mammary carcinoma with brain metastasis and meningeal carcinomatosis was made.     

Myxoid leiomyoma of the iris in a dog

A leiomyoma of the iris is described in an 11-year-old Yorkshire Terrier. This is a rare primary intraocular tumor in dogs and we describe the clinical presentation, gross findings and histopathologic characteristics of this tumor. The diagnosis was made on the basis of light microscopy and immunohistochemical staining using antidesmin antibodies, which is specific for myogenic tissues. An unusual feature of the tumor was the presence of myxoid change. To our knowledge myxoid change has not been previously described in a primary intraocular leiomyoma.     

Pulmonary carcinosarcoma in a cat.

A Domestic Shorthaired cat was presented with coughing and severe respiratory distress. Thoracic radiographs revealed a lobar mass and numerous additional cavitated intrapulmonary masses. The cat was euthanized and submitted for necropsy. Histological examination of the large mass revealed 2 distinct neoplastic components consisting of bronchial adenocarcinoma admixed with neoplastic areas composed of highly atypical undifferentiated spindle cells (sarcomatous component). Simultaneous expression of vimentin and cytokeratin by a subpopulation of neoplastic epithelial cells and by rare neoplastic spindle cells was identified. On the basis of histology and immunohistochemical results, a diagnosis of primary pulmonary carcinosarcoma with intrapulmonary epithelial metastases was made. Pulmonary carcinosarcoma is a well-known pathological entity in humans. It is a rare tumor in animals and has not been previously reported in cat.     

A RETROSPECTIVE STUDY ON THE SONOGRAPHIC FINDINGS OF ABDOMINAL CARCINOMATOSIS IN 14 CATS

A retrospective review was performed on 14 cats with histology- or cytology-proven carcinomatosis. The mean age was 12.7 years with a median of 11 years. The diagnosis of carcinomatosis was made by histology in 11 cats and cytology in three cats. Twelve cats had cytologic examination of the peritoneal free fluid and seven cats (58.3%) had evidence of malignant cells. The primary tumor site was determined in 13 cats. The most common organ locations for the primary tumor were the liver (n = 5), pancreas (n = 3), and small intestine (n = 3). Other sites were stomach and spleen in one cat each. Epithelial cell neoplasia was the primary tumor type in 11 cats. Two cats had abdominal lymphomatosis and one cat had abdominal sarcomatosis secondary to metastatic hemangiosarcoma. Free peritoneal fluid and masses in the connecting peritoneum were found in all cats (100%). Additional findings included primary or metastatic masses in abdominal organs in 10 cats (71.4%), lymph node enlargement in five cats (35.7%), pleural effusion in three cats (21.4%), parietal peritoneal masses in two cats (14.3%), and visceral peritoneal masses in one cat (7.1%). Masses in the connecting peritoneal may be a very specific finding for carcinomatosis in cats, especially with a concurrent abdominal neoplastic mass. Parietal and visceral peritoneal masses, while uncommon in this series of cats, have not been reported for other diseases and seem to strongly support a diagnosis of carcinomatosis.     

Presumptive primary cardiac lymphoma in a cat causing pericardial effusion

We report a case of primary cardiac lymphoma in a cat, causing pericardial effusion. A 13-year-old castrated male Himalayan cat was evaluated for chronic weight loss and radiographic finding of cardiomegaly. Pericardial effusion and a heart mass were detected via echocardiography. Pericardiocentesis and ultrasound-guided fine needle aspirate of the heart mass were performed under sedation. Antemortem diagnosis of cardiac lymphoma was made based on cytology of pericardial fluid. Based on physical examination, laboratory tests and abdominal radiographs, primary cardiac lymphoma was established as the presumptive clinical diagnosis. Treatment with chemotherapeutic agents was initiated.     

FEMORAL OSTEOMYELITIS AND OSTEOSARCOMA IN A DOG

An eight-year-old, female, spayed Golden Retriever was referred to the University of Missouri Veterinary Teaching Hospital for a persistent lameness of 9 days duration. The initial diagnosis made by cytology and culture was Clostridium spp osteomyelitis of the right femoral head and neck. After approximately 1 month of treatment with ampicillin, it was noted radiographically that the lesion was progressing. An excision arthroplasty was done. Histological examination of the surgical specimen revealed osteogenic sarcoma. This case documents the importance of bone biopsy in differentiating osteomyelitis from a primary bone tumor.     

Parotid salivary gland adenocarcinoma with bilateral ocular and osseous metastases in a dog

A case of primary parotid salivary gland adenocarcinoma is described in a three-year-old entire female great dane. The presenting complaint was sudden onset blindness concomitant with the development of bilateral hyphaema and anterior uveitis. A soft-tissue swelling of the left subaural region and right forelimb lameness were also present. A definitive diagnosis of primary parotid salivary gland adenocarcinoma with bilateral ocular metastases was made on post mortem examination. Metastases were also present in the right proximal humerus, left and right prescapular lymph nodes, left axillary lymph node, left retropharyngeal lymph node, bronchial lymph nodes and all lung lobes.     

Metastatic pericardial tumors in a dog with equivocal pericardial cytological findings

A metastatic tumor associated with pericardial effusion was diagnosed in a 6-year-old, female, mixed-breed dog. Echocardiography identified multiple echogenic masses adherent to both visceral and parietal pericardium, while results of pericardial fluid cytology were non-diagnostic. The distribution pattern of the masses is remarkable in that they protruded from both pericardial surfaces, rather than one, and demonstrated an oscillatory motion during the cardiac cycle. Pathological examination confirmed the diagnosis of multiple metastatic tumors of the pericardium, with the primary tumor being an anaplastic gastric adenocarcinoma.     

Bronchiolar adenocarcinoma in a cow

An aged beef cow had a primary lung tumor that was diagnosed postmortem. Clinical signs included inappetence, weight loss, coughing, dyspnea, and reduced lung sounds. Antibiotic treatment was ineffective. The cow was euthanatized. Postmortem examination revealed numerous, firm nodules throughout both lungs. Microscopically, the pulmonary nodules contained neoplastic cells and the diagnosis was bronchiolar adenocarcinoma. A diagnosis of pulmonary neoplasia, although rare, should be considered in an aged cow with similar historical and clinical findings.     

ULTRASONOGRAPHIC EXAMINATION OF CERVICAL MASSES IN THE DOG AND CAT

The ultrasonographic appearance of clinically undifferentiated neck masses for which a definitive diagnosis was eventually obtained in nineteen dogs and one cat is presented in this report. Multiple lesions were seen ultrasonographically in 4 dogs and no cervical abnormalities were seen in 2 dogs resulting in 22 lesions in 20 annuals. Of 7 benign lesions, there were 2 patients with reactive lymph nodes from a regional inflammatory process, and 1 patient each with primary pyogranulomatous lymphadenitis, arteriovenous malformation, foreign body granuloma, cellulitis, and hematoma. Of 15 malignant lesions, 7 were thyroid carcinomas, 3 were lymphomas with submandibular and cervical lymph node enlargement, 3 were lymph node enlargements associated with regional metastasis of malignant tumors, one was a leiomyosarcoma and one was a carotid body tumor. One dog with a diffuse soft tissue swelling of the ventral cervical region had only slight asymmetry of the thyroid lobes on ultrasound examination and no abnormalities of the neck at post mortem. A second dog examined with ultrasound 4 months after surgical removal of a carotid body tumor had no evidence of tumor recurrence. Ultrasonographic examination provided information regarding the character of the lesions, the tissue or organ of origin, and invasion into other anatomic structures. Ultrasound examination in conjunction with fine needle or tissue biopsy provided a definitive diagnosis in those animals in which biopsies were performed.     

IMAGING OF A SPINAL NEPHROBLASTOMA IN A DOG

An 8-month-old German Shepherd dog was presented for investigation of pelvic limb gait abnormality. Neurolocalization indicated a T3-L3 spinal cord lesion. The myelographic appearance was of an intramedullary lesion at T9/10, but upon subsequent magnetic resonance imaging it was determined that the mass was extramedullary. A diagnosis of nephroblastoma was made on histological examination. The imaging features of this rare tumor and the differentiation of intradural-extramedullary and intramedullary masses are discussed.     

Sclerosing peritoneal mesothelioma in a dog - a case report

A case of peritoneal sclerosing mesothelioma in a 3-year-old German shepherd dog is reported. The dog presented a severe abdominal distension. Cytological examination of the peritoneal fluid revealed anaplastic epithelioid cells. Necropsy findings revealed an irregular-shaped mass attached to the pancreas and stomach with numerous nodules covering the intestinal and urinary bladder serosa. The diagnosis was made by histology and immunohistochemistry, with cytokeratin, vimentin and calretinin antibodies. Differential diagnosis with chronic peritonitis and spreading of abdominal primary carcinoma is discussed.     

A true "triphasic" pattern: thoracolumbar spinal tumor in a young dog

An 8-month-old male Bernese Mountain Dog was referred with a history of hindlimb weakness that progressed to paresis on the right side. An intradural mass was detected in the spinal canal at the level of the 2nd and 3rd lumbar vertebrae. During surgical removal, 2 small fragments of the mass were prepared for cytologic examination by the squash technique. Cytologic examination revealed 3 different cell types: mesenchymal (stromal) cells, epithelial cells, and small undifferentiated hyperchromatic cells. On the basis of location and the triphasic cytologic pattern, a diagnosis of spinal nephroblastoma (thoracolumbar spinal tumor of young dogs) was made; histologic examination of the mass confirmed the cytologic diagnosis. To our knowledge, this is the first report of a triphasic pattern in a cytologic sample; recognizing this pattern is an important aid in reaching a definitive cytologic diagnosis.     

Bilateral intraocular malignant neuroectodermal tumors in a telescope goldfish (Carassius auratus)

A 5‐year‐old male telescope goldfish (Carassius auratus) developed buphthalmia of the left eye. An enucleation was performed and a diagnosis of a neuroectodermal tumor was made on histological examination. Although the fish initially recovered, it was killed 49 days postsurgery due to a severe decline in its condition. On histological evaluation of postmortem tissue samples, it was determined that the fish also had a neuroectodermal tumor of the right eye with local invasion of the brain. On immunohistochemistry, the neoplastic cells were positive for S‐100. To the authors’ knowledge, this is the first published case of naturally occurring bilateral intraocular neuroectodermal tumors in a fish.     

Primary corneal malignant melanoma in a horse

A 13-year-old Missouri Fox Trotter gelding of chestnut colour was referred for a 6-week history of blepharospasm and epiphora of the left eye. Due to the presence of irregular corneal masses, superficial keratectomy was performed along with adjunctive strontium-90 beta irradiation and subsequent topical mitomycin C chemotherapy. A diagnosis of poorly melanised malignant melanoma was made based on histopathological examination and immunohistochemistry. There has been no recurrence of the neoplasm over 10 months of follow-up. To the authors' knowledge, this is the first documented case of a primary corneal melanocytic neoplasm in a horse.     

Equine giant cell tumor of soft tissues

During a routine necropsy examination of a 4-year-old standardbred mare, a well-demarcated dermal mass was seen near the right elbow. Grossly, the mass consisted of multifocal variably sized areas of dark brown, firm material that was separated by thin white septa. Histologically, within the individual compartments, there were numerous multinucleated giant cells, macrophages, and free erythrocytes. A diagnosis of giant cell tumor of soft tissues was made.     

Extraosseous osteosarcoma in a maned wolf (Chrysocyon brachyurus).

A 6-yr-old maned wolf (Chrysocyon brachyurus) was diagnosed with an extraosseous osteosarcoma on the lateral aspect of the right thigh. Antemortem radiography revealed a calcified mass with no skeletal involvement. The mass was excised, but visible regrowth of the tumor was evident within 5 wk. Histologic examination and immunohistochemistry, including staining for p53 tumor suppression gene protein, were performed on the excised mass. The maned wolf was euthanized 13 wk after the initial diagnosis. The neoplasm was located in a site commonly used for the delivery of intramuscular injections, including vaccinations. Although no definitive association can be made, it is worth noting this relationship, as vaccine-site neoplasias have been observed in other species, most notably the domestic cat (Felis domesticus).     

Metastatic transitional cell carcinoma in proximal humerus of a dog

Transitional cell carcinoma (TCC) was diagnosed in the proximal humerus of a dog that was presented with persistent right forelimb lameness with no clinical signs of urinary tract involvement. A diagnosis of TCC was made from surgical biopsy of the humeral lesion with subsequent necropsy revealing the prostatic urethra as the primary site of the tumor.